Bill Long of the Wyoming Wetlands Society plucks trumpeter swan eggs from a nest on Grebe Lake in Yellowstone National Park, replacing them with true-to-life replicas. Hatching the eggs in captivity keeps them from being eaten by predators in the wild.

Bill Long carries a captive-raised cygnet in a 5-gallon bucket on the hike Grebe Lake in Yellowstone National Park. Long was about to attempt to “graft” the baby swan into a wild nest, an operation that failed.

Bill Long of the Wyoming Wetlands Society traverses a marshy field on Grebe Lake, the location of the only known nesting pair of trumpeter swans in the park. Long makes the 8-mile round-trip hike several times during the spring and summer to monitor the nest.

Long recovers a cygnet that was rejected by its wild, would-be parents at Grebe Lake in Yellowstone National Park. The failed “grafting” operation was a letdown, but the technique has helped bring the park’s swans away from the brink of extirpation.

Yellowstone trumpeters fight a ‘swan song’

Biologists intervene to keep swans alive in world’s first national park.

ABOVE: The only nesting pair of trumpeter swans in Yellowstone of 2018 swim around their manmade nest platform on Grebe Lake just west of Canyon Village. "Grafting” operations — plucking eggs from wild nests and hatching them in captivity to prevent the eggs from being raided by predators — has helped bring the park’s swans away from the brink of extirpation.

A trio of sprightly two-day-old cygnets hears their new foster parents calling nearby. Instinctively, the young, captive-raised swans jump off a platform and paddle into the chilly waters of Yellowstone National Park’s Grebe Lake.

Bad move.

This is a swan “graft,” an effort to trick the two adult swans into raising the three young now swimming toward them.

But “mom” and “dad” aren’t enthused. Hovering near their man-made nest platform in the lake, the adoptive parents see the fast-approaching youngsters as pests, rather than beloved offspring. Instead of bonding, they start batting at the young.

Suddenly the cygnets are endangered by birds dozens of times their size. Making matters worse, a pair of potentially predacious loons are inching near the defenseless young.

Recognizing a crisis

Grafting trumpeter swan babies into the nests of wild adults is, for now, the way things work in Yellowstone. The trumpeter population here has been on life support for seven years.

Bill Long looks over notes next to the incubators at the Wyoming Wetlands Society’s office in downtown Jackson.

BRADLY J. BONER / NEWS&GUIDE

“At our historic high we had 65 swans in Yellowstone, and we were down to eight or nine” by 2011, Yellowstone Senior Wildlife Biologist Doug Smith said. “To be honest, we were freaking out.”

A gathering of swan experts that year didn’t provide answers, but Smith took action anyway.

National Park Service managers, who prioritize native species and natural processes, don’t take intervention lightly. But in this case, managers chose intervention over possible extirpation. Smith, best known for leading Yellowstone’s wolf program, stepped in because he believed human activity was to blame for at least some of the decline of the park’s population, an icon of trumpeter swan recovery.

At one point in the 1930s trumpeter swans had been killed off almost everywhere in the Northern Rockies but Yellowstone and the nearby Red Rock Lakes National Wildlife Refuge. Now the narrative has flipped, and Yellowstone is investigating why. The leading hypothesis is that too many of Yellowstone’s 4 million annual visitors tromp too close to the shorelines of the park’s few shallow, weedy lakes and streams, displacing swans from their best habitat.

A modified sock with a swan head is used to accustom recently hatched cygnets to foster parents when they are reintroduced in the wild.

BRADLY J. BONER / NEWS&GUIDE

“The areas that used to be good for swans have a lot of people visiting now,” Smith said.

The disturbance pushes trumpeter families out into the middle of lakes, away from protective vegetation and into open water where cygnets are far more vulnerable, he said.

“They get dive-bombed by a bald eagle,” Smith said, “and the bald eagle kills the chicks. I’ve seen this happen, and so has someone in my crew.”

It’s Riddle Lake — just off the main drag between Lewis Lake and West Thumb — where the eagle onslaught has been documented for the past five years. One of just two of Yellowstone’s remaining wild swan pairs nests here, and they’ve managed no better than raising a single cygnet to adulthood in recent history. This year they didn’t nest at all.

Yellowstone made a rather drastic management decision to help the birds, and for the past four years has closed the area to public access through Sept. 15.

“It was tough,” Smith said, “because Riddle Lake is one of the top day hikes in the park.”

Crisis averted, cygnets rescued

Back at Grebe Lake, 27 miles north of Riddle Lake near Canyon, the swans have at least nested.

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Bill Long carries a captive-raised cygnet in a 5-gallon bucket on the hike Grebe Lake in Yellowstone National Park. Long was about to attempt to “graft” the baby swan into a wild nest, an operation that failed.

MIKE KOSHMRL / NEWS&GUIDE

It’s June 19, and a rainstorm the day before put the kibosh on transplanting the three recently hatched cygnets.

Because of the weather delay the young swans spent one extra day in their Wyoming Wetlands Society incubator in the basement of a Pearl Street office building before being escorted north to Grebe Lake. It was 24 hours too long, Bill Long would learn, as the precocious waterfowl grew too rambunctious by the next day.

Chaos ensued as the would-be foster parents at Grebe Lake rejected the trio as invaders. The young swans’ human guardian, Long scrambled to save the cygnets he’d put so much time, money and heart into raising.

The retired Wyoming Game and Fish Department warden drove back the loons by slapping the water with a broom. He imitated the swan parents, calling with “hoos” to draw the cygnets toward him. Eventually, he rounded up the sopping batch of birds just rejected by their host parents.

Crisis averted, but the grafting operation failed.

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Long recovers a cygnet that was rejected by its wild, would-be parents at Grebe Lake in Yellowstone National Park. The failed “grafting” operation was a letdown, but the technique has helped bring the park’s swans away from the brink of extirpation.

MIKE KOSHMRL / NEWS&GUIDE

“We tried to graft babies that were too old,” Long said after the ordeal ended. “Timing is so critical. You have to have the cygnets stay on the nest.

“If they don’t bond,” he said — “Well, you just saw it.”

Welcome assistance

This year Yellowstone’s wild swans won’t raise any young, one setback in the long-term fight to keep the park’s swans from blinking out.

Mankind’s influence on the temperature of the planet may also have a role in the slow, steady decline. Climate change, Smith said, is causing cold, wet springs in Yellowstone, conditions that aren’t conducive to swan nesting. Wetlands are drying out later in the summer, he said, and there’s overall more variability in the weather.

A final hypothesis, also unproven, is that the cessation of supplemental swan feeding at Red Rock Lakes, a wintering site, has trickled down to the regional population.

Long has a decades-long history of raising swans, even dating to when he was posted as a warden near Elk Mountain — well outside of trumpeter’s range. He cofounded Wyoming Wetlands Society 32 years ago, and for the past seven years he has played a central part in Yellowstone’s efforts to keep its trumpeter swan population afloat. The Jackson-based nonprofit works primarily with trumpeter swans and beavers, and is experienced raising its avian subjects in captive settings. Swan ponds in places like the South Park pasture off South Highway 89 and off High School Road are used routinely for this purpose.

Bill Long of the Wyoming Wetlands Society traverses a marshy field on Grebe Lake, the location of the only known nesting pair of trumpeter swans in the park. Long makes the 8-mile round-trip hike several times during the spring and summer to monitor the nest.

BRADLY J. BONER / NEWS&GUIDE

The Grebe Lake nest had been failing time and again in the years leading up to the park’s 2011 intervention. Predation was one suspected cause, as was faulty genetics, but the pair’s shoreline nest was also being inundated as the lake level rose during runoff season. Long suggested building and bedding an in-water platform that would move with the lake level, and Smith signed on.

“Shockingly, next spring, they went right for it,” Smith said. “It was almost like they were desperate for it. I saw tracks in slush ice of the female walking out to it.”

But even with the platform, the Grebe Lake swans’ clutches were failing.

The wolf biologist and retired warden dialed up the human assistance, and began swiping the large, mottled eggs from the trumpeter nest in the days after they were laid.

The cygnets are then hatched in an incubator and grafted back into the nests immediately or returned to the Yellowstone wild when they were 90 or so days old and large enough to survive on their own.

Egg operation

Long strapped on waders June 6 this year to recover the Grebe Lake birds’ eggs.

He grasped a broom in one hand for self defense against protective parents that can top out at over 25 pounds, and a towel-lined 5-gallon pail to carry the eggs in the other. The first phase of the graft, recovering the eggs, went smoothly. Mom and dad swam nearby noisily hooing, but nothing more.

Bill Long of the Wyoming Wetlands Society plucks trumpeter swan eggs from a nest on Grebe Lake in Yellowstone National Park, replacing them with true-to-life replicas. Hatching the eggs in captivity keeps them from being eaten by predators in the wild.

BRADLY J. BONER / NEWS&GUIDE

“It’s the last of the Mohicans, right here,” Long said back at the shore.

“Three of them,” he said. “That’s a classic number for old birds, so that’s good. None of them smell, so that’s good, too.”

Long’s gloved hand gingerly wrapped Yellowstone’s only three trumpeter eggs from 2018 into Kmart tube socks to keep the clutch warm during a deadfall-ridden 4-mile hike back to the Grebe Lake trailhead.

Once hatched, these cygnets will not return to their parents. Instead, to supplement the genetics of trumpeter swans that have navigated at least two population bottlenecks, Long will swap in Jackson Hole cygnets in their place.

The plan was to raise the wild cygnets at captive ponds and then release them in the Hayden Valley come fall.

In Jackson, Long and his Wyoming Wetlands Society colleagues know just what to do with the eggs. They’ve hatched over 700 cygnets in incubators that hover just shy of 100 degrees. Imitating mom’s natural routine, eggs are turned over and rotated 180 degrees every two hours, except during the night. They’re regularly misted with water to imitate the wet plumage from mom’s underside. That’s the task, for about a month, until the cygnets beak their way through the eggshell.

Long slides a swan egg he has retrieved into a gym sock to protect it during the 4-mile journey back to the trailhead.

BRADLY J. BONER / NEWS&GUIDE

Over the years most of the cygnets haven’t been released in Yellowstone park itself, but rather along the fringes of a tristate trumpeter swan population that covers much of the larger ecosystem. Deep pockets are underwriting the restoration effort. Walter Wehtje, who directs the Ricketts Conservation Foundation, has budgeted $2.5 million over the next decade to support Long’s work.

“The partnership’s long-term goal is to, within the next 10 years or so, have produced enough swans that we can call the reintroduction program completed,” Wehtje said.

The plight of Yellowstone’s swans — a “shocking” piece of news, he said — is partially what attracted the philanthropic group.

A turnaround

The 2017 nesting season was a total flop, because the big snow year kept Yellowstone’s lakes locked in ice into the nesting season. This year’s grafting attempt failed. But the technique is mostly working. Releases of fledged adolescents are also augmenting numbers. Yellowstone’s swans have turned a corner.

Bill Long carries three swan eggs over dead and downed lodgepole pine trees on the banks of Grebe Lake in Yellowstone National Park.

BRADLY J. BONER / NEWS&GUIDE

“We went from single digits in the population, to now we’re in the mid-20s,” Smith said. “We’ve saved them in the short-term.”

Trumpeters typically don’t breed until they’re 3 to 5 years old, which means the first Wyoming Wetlands Society birds are just now coming of age. Some have paired up and established territories, but through 7 years of intervention, eggs in new nests have not yet materialized.

“They’re a bird that teaches you patience,” Smith said. “I’m sitting here still waiting for them to form new pairs and breed. I’m like, ‘Come on man, give me a break, birds, get going.’”

The goal is to build the population up to something more sustainable.

“I’m sorry for a really bad pun, but right now all our eggs are really in two baskets,” Smith said. “I’d like to have six or eight baskets out there.”

Ending the intervention hinges partly on meeting those goals, but it also depends on what emerging science says about why the swans are struggling.

This summer Yellowstone turned loose an avian biological technician, Evan Shields, to investigate the nuanced and mysterious decline. He’ll explore Yellowstone’s historic swan dataset — the most thorough of any bird species — and monitor swan breeding pairs inside and outside the park to get a better grip on conditions that lead to the swan struggles. Perhaps, Smith pondered, Yellowstone’s just a high plateau peppered with substandard swan habitat.

“Is Yellowstone all bad sites,” he said, “or is it a mix of bad and good, and there’s hope?”

Swan complications

At the Grebe Lake trailhead Long moved the cygnets he scrambled to save from the bucket into a mobile incubator. Although the clutch was rowdy and boisterous on the hike in — one even jumped ship — they’re tuckered out and silent on the hike out.

“I’m glad we salvaged them,” Long said. “It’s bad enough they didn’t graft. To lose cygnets would have been a travesty.”

Using a technique called “candeling,” Long can estimate how far along the cygnets are in their development inside their egg. The dark spot on the egg is the cygnet’s head.

BRADLY J. BONER / NEWS&GUIDE

Although the long-term effort to keep wild swans in Yellowstone is working, setbacks keep cropping up.

Smith and Long intended to set some fledged cygnets free later in the summer, but the three eggs Long carefully collected from Grebe Lake won’t be part of that cohort. While more than 80 percent of the hundreds of incubated trumpeters Wyoming Wetlands Society has reared manage to hatch and survive, the Yellowstone eggs did not.

One Grebe Lake cygnet essentially suffocated in the egg while breaking free. The remaining two died three days later for unknown causes. Long is determining the cause of death, and though he’s got his hunches he’s not anticipating any straightforward answers.

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(13) comments

The article states humans trampling areas close to the waters the swans like as a reason why their numbers are plummeting in YNP. But no mention of the 'Native Fish Conservation Plan' of 2010 which includes lots of humans trampling around electroshocking, applying rotenone (fish poison), restocking fish and monitoring. This should certainly be considered as a stressor on the birds. Grebe Lake mentioned in the article just went through this process in 2017.

Swans, whether you care to admit it or not, rely on vast, open farmlands both for safety (they can see those non-wolves and coyotes from a long way off) and for sustenance (they eat the leftover grains, bugs and worms that go hand in hand with agriculture).As liberal legislators continue to raise property and inheritance taxes, more and more families are forced to sell their heritage farms to real estate developers so that Mc Mansions can be built. Obviously, no grains, no bugs, no worms and no “safe spaces” remain for the swans.The largest population of migrating Trumpeter Swans in the world, winter along Puget Sound in Washington State. Guess what???Liberal legislators continue to raise property and inheritance taxes on farmland and more and more families are forced to sell their heritage farms to real estate developers.Now, for the good stuff! Originally, the land along the Puget Sound was NOT farmland but heavily timbered old-growth forest.The swans used to over-fly Washington in favor of tidal flats and swamps. I’m betting the swans are not an aboriginal species to the Yellowstone Park area but were driven into the park by shrinking farmland around the Teton Valley(s).So, for whom am I to feel sorry?

Ahhh, It's now the "liberals" fault that the ESA worked so well that Bald Eagles are killing swan chicks in the middle of a National Park. Got it. BTW, when all the farming subsidies go away, so should all the taxes. No exemptions for equipment, no H1B for cheap labor, no exemption for fuel, on and on. And, BTW, it was the Republicans who raised property taxes, by 5.5 billion, on the entire state in 2018. Yep, go check the minutes. My property taxes went up significantly because of the republicans in WA state. So, I'm paying higher taxes and subsidizing industry. On to Swans. The Trumpeters in YNP are native to that area. As stated above predation on the young and people stomping the shorelines are the two major forms of mortality. nest flooding is another. As for depredation every single other animal in the park the eats meat will raid a nest full of eggs, so if the animal can't nest, it doesn't matter if it has massive fields of grain to stand around in, it's not going to reproduce. Biology, another liberal conspiracy. Finally, Snow Geese use the same farmland resting zones that swans do, and snow geese are listed as least concern. Basically because there are so many of them that they drive farmers nuts. The snow geese must be conspiring with liberals to take out the swans.

Park biologists admitted that the resident birds at the west entrance bridge were killed by wolves, but blamed the continuing decline on other things such as AGW and severe winters. Is there a breakdown of the population for the last 30 years that would start before the wolves were planted.

What an inspirational article! Certainly blaming the wolves can't help. All of nature's creatures peacefully coexist in perfect balance. We should look to human activity as the constant culprit in the destruction of our ecosystems.

To believe that "all of nature's creatures peacefully coexist in perfect balance" is naïve foolishness. Nature's creatures are hungry. They eat one another. Being eaten alive is as far as I can imagine from "peaceful coexistence"! Geeze...

Yes, @Konrad you are correct. "Peaceful" wasn't an optimal choice of words, at least from a human point reference. As we all know, violent deaths are an integral part of nature, they are part of maintaining a perfect balance. The larger point: it is ridiculous to blame wolves for the death of prey that naturally occur in their habitat.

Actually none of the early explorations documented a single wolf. Lt. Doane who led the first expedition kept a record of every creature they saw, and NO wolves were mentioned. However President Roosevelt did mention seeing a mountain lion eating on an elk carcass in 1903. They did not seem to even show up much until humans moved west and evidently they were pushed out of the areas to the west by increasing settlers. Several VIPs, including several Generals made a trip to the new park in 1875, a primary goal being the killing of wolves. The only wolf they saw was from the train on the prairie coming out of Cheyenne. They spent nearly a month in the park, never saw nor heard one. That book in 1875 was authored by Gen. W.E. Strong. Battle Drums and Geysers contains the Washburn Expediton led by Lt Doane, which was the first actual exploration of the YNP area and was very important to getting that area made a NP.

The wolves are not taking out the swan babies because. Please reread the article. People walking around the shoreline and bald eagles eating the chicks are taking out the swans. Wolves may get an occasional bird, but wolves aren't bird hunters as a rule. If a wolf got one then it was an opportunistic event, thus rare. Coyotes now, those will raid nests. And the wolves have checked the coyote population in YNP, so thank the wolves for that.